2.2 billion

— Metric tons of CO2 equivalent emitted by U.S. power plants in 2011, according to new numbers from the Environmental Protection Agency (EPA).

Paul Souders

Coal-fired power plant in West Virginia.

That’s a 4.6% decrease from the previous year, thanks largely to the relative decrease in carbon-heavy coal and an increase in cleaner-burning natural gas and renewable energy sources. The drop in carbon emissions is notable given that the U.S. still has no national climate policy, with carbon cap-and-trade failing in Congress back in 2010. But fracking has helped produce rock-bottom prices for natural gas, and combined with tougher air pollution regulations from the White House, utilities have been able to make some progress cleaning up the national power supply. Not that much progress though—the EPA’s report noted that just 4% of the 8,000 factories, refineries and power plants surveyed were responsible for more than half of U.S. greenhouse gas emissions. And the biggest polluters are big ones—two Southern-owned coal-fired plans in Georgia and Alabama topped the list, emitting some 22 million tons of CO2 equivalent. Or about the total national emissions of Ghana.